EXPERIMENT 5: RECRYSTALLIZATION 83 The purpose of this assignment is to help you form a clear idea of this very important lab technique of purification by recrystallization. 1) Weigh the crude sample. 2)... 3)...etc. (last step) Weigh the recrystallized sample and calculate the percent recovery 3. In the introduction, it was mentioned that the ideal solvent should be "capable of dissolving impurities entirely or not at all." a) Explain how the impurities are separated from the sample in the case where the solvent is capable of dissolving the impurities entirely, b) Explain how the impurities are separated from the sample in the case where the solvent cannot dissolve the impurities at all. 4. In the introduction, it was stated that the ideal solvent should "have a boiling point that is lower than the melting point of the solute." Explain why this is so. 5. Why must the solution be cooled slowly to room temperature at first, before cooling it further in an ice bath? 6. Even if you do not know what the accepted melting point should be, how can you tell, from your mp data, whether the final sample is pure?